As a multi-layer piezoelectric element, as shown in FIG. 7, there is known a construction comprising: a stacked body 6 including an active section 4 composed of a of piezoelectric layers 2 and internal electrode layers 3, and an inactive section 5 disposed at each end in a stacking direction of the active section 4; an electrically-conductive bonding material 7 disposed on a side surface of the stacked body 6 so as to extend from the active section 4 to the inactive section 5; and a flat external electrode plate 80 attached, through the electrically-conductive bonding material 7, to the side surface of the stacked body 6 (refer to Patent Literature 1).